The high expression of HOX genes in NPM1-mut AML cells requires the presence of the delocalized NPM1 mutant protein; in fact, pharmacological inhibition of the XPO1-relocalized NPM1 mutant protein in the nucleus results in the immediate downregulation of HOX gene expression, the differentiation of AML cells, and the prolongation of the survival of NPM1-mut leukemic mice [11]. The gene discussed is XPO1; the disease is acute myeloid leukemia.